Machinery for grinding knives which have warped surfaces



UNITED STATES PATENT oEEroE.

WILLIAM HOVEY, OF VORCESTER, MASSACHUSETTS.

MACHINERY FOR GRINDING KNIVES WHICH HAVE WARPED SURFACES.

Specification of Letters Patent No. 5,398, dated December 18, 1847.

To all whom t may concern:

Be it known that I, IVILLIAM HovEY, of the town and county of lVorcester and State of Massachusetts, have invented a new and useful machine for grinding and finishing the edges of knives or blades, such as are used on what are called cylinder cutters or shears, without removing them from the stock or cylinder where t-hey belong, and that the following is a full, clear, and exact description of the principle or character which distinguishes it from all other things before known and of the manner of making,

constructing, and using the same, reference being had to the accompanying drawings, making part of this specification, in which- Figure l is a perspective representation of the machine, and Fig. 2, a longitudinal vertical section of the same, taken through and in the line of the axis of the grinder.

The same letters indicate like parts in all the figures.

My present invention consists in arranging the grinder so that it shall receive in addition to its rotary a reciprocating motion in the line of its axis to pass its surface over that portion of the knives attached to a stock and held in appropriate boxes or between centers in a carriage which moves from end to end under the grinder and at right angles to its axis, the knife which is under the operation of the grinder being supported by a bed or gage plate which insures the grinding of the edge of each knife to the same distance from the axis of the stock to which they are attached.

In the accompanying drawings (a) represents a frame properly adapted to the operative parts of the machine, and (b) a carriage which slides crosswise on ways attached to a portion of the main frame, there being a screw (c) by which the position of this carriage can be set nearer to or farther from the grinding wheel And this carriage is provided with ways at right angles to the ways on which it moves to receive another carriage (e) provided with boxes or center screws (e) to receive the stock of knives and this carriage receives a longitudinal regi rocating motion by being engaged by a cate lever (g) with the threads of a screw (7L) that has its bearings in a standard (L) on the lower carriage (b) and is provided with a pulley (if) which receives motion by a belt from a pulley (j) on the shaft which receives motion from the main driving shaft (12') by a worm and cogged wheel The drum (o) on the main driving shaft communicates a rapid motion to the grindingwheel (d) by a strap (p) running out to a pulley (g) on its shaft (1") the journals of which are longer than the boxes in which they run that it, with the grinder may receive an endwise reciprocating motion which is communicated to it by a lever (s) embraced by a collar (t) and is jointed to another lever which receives a vibrating motion from a crank (e) on the shaft (73) by a connecting rod (w).

The grinding wheel turns with the usual velocity of a -grindstone and vibrates with its shaft as the carriage with the stock of knives moves from end to end. The knives on the stock are placed one by one in succession on the guard rest or gage and passes under the grinder while it rotates and vibrates, the vibration being essential to prevent the grinding surface from becoming uneven and to insure the proper grinding of the knives. The motion of t-he under carriage by means of the set screws or their equivalent is for the purpose of adjusting the edges of the knives to the guard rest or gage and to adapt the machine to different diameters.

The object for which this machine was first contemplated and designed, is to grind and perfect the edges of the knives such as I use in my straw cutter after they are attached to the stock or cylinder of the same in order to make their edges perfectly cylindrical. The manner in which I use this machine for this purpose is as follows. In order to prepare the knives for this operation I attach them to a stock which belongs to my first grinding machine, one at a time and in that machine I grind them to a flat thin bevel edge. They are then taken from the stock of that grinder and attached to the stock of the straw cutter which constitutes the cylinder of knives. (The first grinder was patented Sept 23, 1845, and'is found to be an invaluable machine in the manufacture of knives for cylinder straw cutters. Reference is hereby had to the specification, drawings and model at the Patent Office.) I the-n apply this cylinder of knives to my last grinder in the manner above described, and by giving them a little shorter bevel, the grinding is perfected and but very little of the edge of the knives taken away.

It is obvious that this principle will apply to the grinding of any kind of cylinder knives or shears, such as are used for shearing cloth and for other purposes and that it can be applied to grinding the knives of straw cutters by attaching them to a stock like the one in my irst grinder to prepare the bevels and then transferring them to the straw cutter stock and finishing them as above described; or they can be Wholly ground and finished on t-he cylinder of the straw cutter or other cylinder stock.

Vhat I claim as my invention and desire to secure by Letters Patent, is-

The application of the grinding Wheel vgage Vrest constructed substantially in the manner as above described and for the purposes herein specified.

WILLIAM HOVEY. Vitnesses:

CHAS. 7. I-IARTsi-IORN, JOHN C. B. DANIELS. 

